Question for a physicist.

This is why the argument doesn’t ring true for me. Imagine there’s nothing in the cosmos except empty space and Major Tom floating in his tin can - if we spin the craft (regardless of there being nothing but empty space to spin it ‘relative’ to), he experiences centrifugal force.

If that doesn’t work, then let’s try this; there’s nothing in the universe except empty space, Major Tom in his tin can, and *a tiny grain of dust *positioned 100 yards away from the craft.

Now we can spin the craft at one revolution per second ‘relative’ to the grain of dust - and the brave pilot experiences some centrifugal force, but it would be absurd to describe the craft as stationary and that force instead being caused by an orbiting grain of dust, wouldn’t it?

It depends on whether you understand that the pseudo-forces induced by the change into a non-inertial reference frame are fictitious, and why and how they arise. In order to do this you first need a description in the non-inertial reference frame (the “correct” frame without fictitious frame-dependent effects) anyways. Furthermore, the description in the non-inertial frame is simpler because all of the forces are described by the known laws of physics rather than by additional pseudo-forces only motivated by the particular choice of non-inertial reference frame.

For example if you live on a merry-go-round, you feel centrifugal and coriolis forces. The only way you can understand these forces in terms of the known laws of physics is by realizing you are in a spinning (non-inertial) reference frame. The description in the non-inertial reference frame is simpler, because it is consistent with the known laws of physics and doesn’t require strange additional pseudo-forces.

ETA: directed at Mijin

This is conceptually historically false, and highly misleading. When the heliocentric system was introduced by Copernicus it most certainly did mean circular orbits around the Sun. It meant that to Tycho Brahe and Galileo too, and, indeed, everybody who supported it until such time as Kepler decisively demonstrated the advantages of ellipses. (Galileo even knew about the ellipse based system of Kepler, but rejected it as absurd, because he so firmly believed natural motion to be circular.)

Heliocentrism, as such, did not get rid of complications such as epicycles, and you are just plain wrong to imply that it did or does. It was a necessary step towards the ellipse based heliocentric system of Kepler, which did dispense with the epicycles, but heliocentrism itself does not get you there. Kepler’s move to elliptical orbits was a major conceptual revolution, comparable in difficulty and importance to Copernicus’ move to heliocentrism.

(And although Kepler’s work did, in fact, get rid of the complications of epicycles, that was not particularly his aim. He was just trying to achieve an accurate mathematical description of the detailed observational data, and was quite prepared to consider hypotheses that were even more mathematically complex than the systems of Copernicus and Ptolemy. Nature cannot always be relied upon to be simple and elegant. Just ask a biologist.)

You are right, of course, that geocentrism is incompatible with Newton’s laws (and that is very relevant to OP’s question), but the way you put it gets things backwards. Newton was able to discover his laws only because of the prior work of Kepler that established that planets move in ellipses around the Sun. Newtonian gravitational theory derives (historically, and in Newton’s mind) from heliocentrism and Kepler’s Laws, not vice-versa as you imply.

Your argument with me here is completely bizarre. I have no idea how your last few sentences are in any way inconsistent with me correctly saying that heliocentrism is a necessary condition for the removal of the above mentioned complications. Perhaps for pedants I should have said “necessary but not sufficient”, but this I thought should have been pretty obvious, as well as unnecessary for the purposes of answering the OP.

And what do you mean “not vice-versa as you imply”? How did I imply anything other than exactly what you just wrote??

njtt, I think your long reaction to my post is derived from a different usage of the term ‘heliocentrism’, which is just plain silly. I am just using it in the sense “earth goes around the sun” as opposed to “sun goes around the earth” (as I think was intended by the OP) rather than all of the historical connotations you are using. I hope you can agree with the sentiment that I expressed, which is simply that geocentrism requires complications that are not required when the assumption is that the earth orbits the sun rather than the other way around. With the new assumption, Kepler’s observations are possible, and so on…